Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Nebraska - Lincoln (2445)
- Singapore Management University (2302)
- Brigham Young University (1907)
- TÜBİTAK (1302)
- Wright State University (1051)
-
- Old Dominion University (968)
- Missouri University of Science and Technology (868)
- University of Kentucky (787)
- Utah State University (766)
- Portland State University (746)
- University of Nevada, Las Vegas (714)
- Edith Cowan University (655)
- University of South Florida (648)
- Montana Tech Library (600)
- City University of New York (CUNY) (597)
- Technological University Dublin (566)
- University of Central Florida (555)
- Air Force Institute of Technology (538)
- Louisiana State University (526)
- Embry-Riddle Aeronautical University (490)
- University of Arkansas, Fayetteville (479)
- Nova Southeastern University (459)
- Chulalongkorn University (456)
- University of Texas Rio Grande Valley (440)
- San Jose State University (374)
- California Polytechnic State University, San Luis Obispo (369)
- Western Kentucky University (367)
- Claremont Colleges (349)
- Purdue University (348)
- New Jersey Institute of Technology (345)
- Keyword
-
- Machine learning (527)
- Artificial intelligence (362)
- Sustainability (333)
- Social media (290)
- Climate change (274)
-
- Machine Learning (265)
- Cybersecurity (241)
- Deep learning (230)
- Education (229)
- Computer Science (205)
- Security (205)
- Chemistry (193)
- Mathematics (188)
- Privacy (183)
- Twitter (179)
- Artificial Intelligence (175)
- Priority Soils (172)
- Nanoparticles (168)
- Natural language processing (167)
- Computer science (160)
- COVID-19 (158)
- Statistics (144)
- Technology (142)
- United States (137)
- Environment (134)
- Groundwater (128)
- AI (122)
- Applied sciences (121)
- Water quality (119)
- Western Kentucky University (110)
- Publication Year
- Publication
-
- Theses and Dissertations (3160)
- Research Collection School Of Computing and Information Systems (2051)
- Electronic Theses and Dissertations (747)
- Turkish Journal of Chemistry (642)
- Silver Bow Creek/Butte Area Superfund Site (561)
-
- Kno.e.sis Publications (540)
- Dissertations (482)
- Faculty Publications (443)
- Chulalongkorn University Theses and Dissertations (Chula ETD) (395)
- USF Tampa Graduate Theses and Dissertations (378)
- Turkish Journal of Electrical Engineering and Computer Sciences (349)
- Walden Dissertations and Doctoral Studies (329)
- Masters Theses (326)
- Theses (315)
- LSU New Orleans Theses and Dissertations (312)
- LSU Doctoral Dissertations (300)
- Articles (289)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (269)
- Open Access Theses & Dissertations (265)
- Journal of Electrochemistry (264)
- All Works (262)
- CCAC Theses and Dissertations (245)
- Coal Geology & Exploration (237)
- Graduate Theses and Dissertations (230)
- Dissertations and Theses (226)
- Honors Theses (217)
- Master's Projects (210)
- Publications (208)
- IGC Proceedings (1977-2023) (206)
- Doctoral Dissertations (197)
- Publication Type
Articles 40621 - 40650 of 40779
Full-Text Articles in Entire DC Network
The Effect Of Nutrient Levels In Nutrient Cultures On The Translocation Of Foliar Applied Nutrients, David D. Neher
The Effect Of Nutrient Levels In Nutrient Cultures On The Translocation Of Foliar Applied Nutrients, David D. Neher
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Since man first grew crops on calcareous soils he has probably been troubled with what we today call lime-induced chlorosis. This chlorosis has determined whether he grew certain desirable ornamentals or crops or whether he had to substitute others which were less desirable.
Lime-induced chlorosis is spread world wide. It has been reported in the vine and fruit growing regions of Europe, in the chernozem soils of Russia, and many other areas where the rainfall is relatively low and the soil is relatively high in calcium carbonate. In the United States it most frequently occurrs where the average annual rainfall …
A Comparison Of Internal Bicarbonate Of Some Chlorosis-Resistant And Chlorosis-Susceptible Plants, Ralph Barlow Clark
A Comparison Of Internal Bicarbonate Of Some Chlorosis-Resistant And Chlorosis-Susceptible Plants, Ralph Barlow Clark
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Iron chlorosis has been a srious problem for many years. This physiological disease has occurred so frequently on calcareous soils that it has been called lime-induced chlorosis by many of the workers. Because the western United States has so many soils of this type, the chlorosis problem has been of primary concern. Untold economic losses have been the result of this physiological disease.
Interveinal yellowing of the leaves along with loss of plant vigor and retarded growth characterize the disease. In severe cases die-back of the terminal growth and eventual death of the plant result. No single factor has been …
The Influence Of Age On The Cation Exchange Capacity Of Plant Roots, Einard S. Haniuk
The Influence Of Age On The Cation Exchange Capacity Of Plant Roots, Einard S. Haniuk
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A yellowing which develops in some plants growing on naturally calcareous soils is called lime-induced chlorosis. The problem is complex, as indicated by Brown and Holmes (1956) and Porter and Thorne (1955). Species and varieties of plants differ in their iron requirements, susceptibility to lime- induced chlorosis, and inter acting soil f actors which affect iron supply (Thorne et al 1950). Chlorosis of plants does not appear, therefore, to stem from a common causative factor. At least a part of this difference has been found to be associated with the plant roots. Thus, through the use of resistant root stock …
Engineer Intelligence Study No. 191, Terrain Analysis, Alaska Slope Region, Alaska, 1959, Military Geography Branch, Usgs, Robert Bolin , Depositor
Engineer Intelligence Study No. 191, Terrain Analysis, Alaska Slope Region, Alaska, 1959, Military Geography Branch, Usgs, Robert Bolin , Depositor
United States Department of Defense Military Intelligence
The summary on Page 5 is paraphrased as follows. This digital document is a generalized description of the Arctic Slope region -- an area covering approximately 70,000 square miles. Access to the region and the feasibility of various access routes are discussed. Location and extent of natural fuel supplies are given. Factors controlling outdoor work feasibility are summarized graphically on Page 19. A terrain analysis of each of the three major physiographic provinces of the region. Those provinces are the Arctic Coastal Plain, Arctic Foothills, and Brooks Range provinces. Geographic factors which affected cross-country movement, construction, and water supply within …
East Texas Tuberculosis Hospital Scrapbook, University Of Texas Health Science Center At Tyler
East Texas Tuberculosis Hospital Scrapbook, University Of Texas Health Science Center At Tyler
Health Science Center Records
A wood bound scrapbook that documents the happenings and lives of patients, volunteers, and workers who lived and worked in the East Texas Tuberculosis Hospital. Contains photographs, letters, newspaper clippings, and flyers.
Report Of Engineering Research With Recommendations For Strengthening The Program, Vaughn E. Hansen
Report Of Engineering Research With Recommendations For Strengthening The Program, Vaughn E. Hansen
Reports
Progress of Engineering Research: The growth initiated with the reorganization of the Engineering Experiment Station in 1957-58 has been stready and consistant through 1958-59. Every sign points to continued expansion through the coming year. This growth is shown in Table 1. The number of active projects this year has increased to nineteen, the funds allocated for Engineering research were $53,861 plus $17,826 to contract research, exclusive of approximately $75,000 in the Agricultural Experiment Station. The number of staff members engaged in research is now twelve. Contract research money has been obtained to finance four projects which were financed previously with …
Spectrophotometric Study Of The Boron- Curcumin System, Frank Xavier Pollio
Spectrophotometric Study Of The Boron- Curcumin System, Frank Xavier Pollio
Master's Theses
In the present research project an attempt has been made to determine the mechanism of the reaction followed in the curcumin spectrophotometric method for boron determination using a modification of Naf'tel's method.
Spectrophotometric Study Of The Boron-Curcumin System, Frank Xavier Polio
Spectrophotometric Study Of The Boron-Curcumin System, Frank Xavier Polio
Master's Theses
With mechanism and structure in mind, the aim of this research project was to investigate the role played by the various reagents used in the curcumin spectrophotometric method. The reagents were used in varied concentrations and at times some eliminated entirely, in the hope that a greater understanding be gained in the overall mechanism followed by the reaction.
One of the major objectives was to try to determine the structure of the colored substance formed in the reaction. A step towards this goal was gained by obtaining molar ratios of the entities suspected to be an intricate part of the …
The Bromination Of 1,1,1-Ethanetriacetic Acid, John A. Gurney
The Bromination Of 1,1,1-Ethanetriacetic Acid, John A. Gurney
Theses and Dissertations
Essential to the entire field of Organic Chemistry is the nature of the carbon to carbon bond. Our current concepts and guiding principles concerning it are almost solely constructed from aliphatic compounds, certain simple ring species, and aromatic systems. Except for special cases, aliphatic and aromatic types are felt to be mildly strained or free from internal tension while the alicylic small and medium ring compounds are the so-called strained molecules. These strained compounds involve bending back or compression of two of the four carbon bonds from an equilibrium position. Distortions of more complex origin occur in the paracyclophanes and …
An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane
An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The movement of water in soil presents many interesting problems to the research worker. It is also a subject which finds wide and important application in agriculture and several branches of engineering.
The object of this work was to examine the usefulness of a new equation of flow of water in unsaturated soil. If valid, this new approach may be able to eliminate some of the gaps in our present knowledge of the subject.
All soil lying above the capillary fringe of a water table is in the unsaturated state with respect to water. This means that in any macroscopic …
Physics, Chapter 37: Reflection And Refraction, Henry Semat, Robert Katz
Physics, Chapter 37: Reflection And Refraction, Henry Semat, Robert Katz
Robert Katz Publications
In the passage of a beam of light through a medium, some of the radiant energy is absorbed and is transformed into internal energy, while some of it is scattered in all directions. The oscillating electric field associated with the light wave sets some of the electrons of the medium into oscillation, thus giving up some of its energy, and these oscillating electrons subsequently reradiate energy as scattered electromagnetic radiation. Scattering therefore takes place only in the presence of matter. The color of the sky is due to the small amount of scattering of sunlight by the molecules of the …
Variation In Tracheid Length And Wood Density In Geographic Races Of Scotch Pine, Robert M. Echols
Variation In Tracheid Length And Wood Density In Geographic Races Of Scotch Pine, Robert M. Echols
Yale School of the Environment Bulletin Series
No abstract provided.
Physics, Chapter 25: Capacitance And Dielectrics, Henry Semat, Robert Katz
Physics, Chapter 25: Capacitance And Dielectrics, Henry Semat, Robert Katz
Robert Katz Publications
When an isolated charged conducting sphere bears a charge Q, the potential of the sphere may be computed from the results of Section 23-6 by considering that the electric intensity outside the sphere is as though the entire charge of the sphere were concentrated at its center.
Liesegang Rings, Robert Edward Young
Liesegang Rings, Robert Edward Young
Masters Theses
"Although the discovery of the "Liesegang Rings" phenomenon was made sometime before 1855 little was done in the way of study or experimentation until 1896 when R. E. Liesegang discovered that if a crystal or strong solution of silver nitrate is added to a gelatin gel containing dilute potassium chromate, the resulting precipitate of silver chromate is not continuous, as might be expected, but forms a discontinuous periodic pattern. This pattern follows a geometric progression law, xn = akn, where xn is the position of the nth ring, and a and k are constants. K …
Physics, Chapter 20: Wave Motion, Henry Semat, Robert Katz
Physics, Chapter 20: Wave Motion, Henry Semat, Robert Katz
Robert Katz Publications
Wave motion is an important method of transferring energy from one place to another without involving the actual transfer of matter. When a pebble is dropped into a still pool, some of the kinetic energy of the pebble is used to generate the ripples which spread out in all directions over the surface of the pool. When the ripples pass by a floating object, such as a bit of cork, the cork bobs up and down, having acquired its kinetic energy of vibration from the ripple system. The ripples thus serve to deliver some of the energy of the pebble …
Physics, Chapter 41: Polarized Light, Henry Semat, Robert Katz
Physics, Chapter 41: Polarized Light, Henry Semat, Robert Katz
Robert Katz Publications
The phenomena of interference and diffraction show that light is propagated as a wave motion, but they do not show whether light is a longitudinal wave or a transverse wave. The fact that the velocity of light is the same as the velocity of radio waves and the radiation of visible light from accelerated electrons, as in a betatron, indicates that light is an electromagnetic wave. We recall from Section 20-9 that a wave can be shown to be transverse if a device can be found which will prevent passage of the wave in one orientation and will allow the …
Physics, Chapter 40: Light As A Wave Motion, Henry Semat, Robert Katz
Physics, Chapter 40: Light As A Wave Motion, Henry Semat, Robert Katz
Robert Katz Publications
Let us recount some of the characteristics of the motion of particles and the propagation of waves, with a view toward analyzing the behavior of light. In accordance with Newton's first law, a particle moves in a straight-line path in the absence of external forces. Thus we might infer, as Newton suggested, that light is composed of particles, and that, in a continuous medium, there is no deflecting force on the light particles. At the interface between two media, light may be propagated in a straight line parallel to the interface. Thus even at an interface there is no force …
Physics, Chapter 38: Mirrors And Lenses, Henry Semat, Robert Katz
Physics, Chapter 38: Mirrors And Lenses, Henry Semat, Robert Katz
Robert Katz Publications
A spherical mirror consists of a small section of the surface of a sphere with one side of the surface covered with a polished reflecting material, usually silver or aluminum. If the outside, or convex surface, is silvered, we have a convex mirror; if the inside, or concave surface, is silvered, we have a concave mirror, as shown in Figure 38-1. Most mirrors used commercially are made of glass, with the rear surface silvered and then coated with a layer of paint or lacquer for protection. Mirrors for astronomical telescopes (')f other accurate scientific work are provided with a reflective …
The Preparation And Catalytic Properties Of Rhenium Blacks Obtained By Reduction Of Re(Vii) In Anhydrous Ammonia And Amines With Alkali Metals, David William Seegmiller
The Preparation And Catalytic Properties Of Rhenium Blacks Obtained By Reduction Of Re(Vii) In Anhydrous Ammonia And Amines With Alkali Metals, David William Seegmiller
Theses and Dissertations
The purpose of the investigation was to determine the catalytic activity of rhenium blacks obtained by reduction of rhenium salts in alkali metal-ammonia or amine systems. A review is presented on the chemical, physical and catalytic properties of rhenium, and on the rhenide ion, on the nature of the alkali metal-liquid ammonia system, and the reduction of metallic salts therein. The first reduction system studied was that obtained by dissolving sodium in liquid ammonia. The salts reduced in this system were KReO_4, Re_2O_7 and NH_4ReO_4. The reduction of KReO_4 was unsuccessful, and the heptoxide was difficult to handle. The product …
Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson
Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson
Theses and Dissertations
This investigation showed that a single bacterium was capable of sulfide oxidation in exposed ore bodies. This single bacterium was isolated and characterized. It exhibited different characteristics than any previously known organism. It was found to be a chemosynthetic autotroph. An optimum nutrient concentration was determined for pyrite oxidation. The nutrient concentration was determined for pyrite oxidation. The nutrient contains only a source of phosphate and nitrogen. Urea was found to be a better source of nitrogen than ammonium sulfate which had previously been used. The effect of various organic compounds on the oxidation of pyrite was observed. Glucose and …
An Investigation Into The Effects Of Ultrasonic Sound Waves On The Electrolytic Oxidation Of The Ferrous Ion, David Joseph Leestma
An Investigation Into The Effects Of Ultrasonic Sound Waves On The Electrolytic Oxidation Of The Ferrous Ion, David Joseph Leestma
Bachelors’ Theses
Upon becoming interested in the use of ozone as an oxidizing agent, the author found a reference in the current literature to the production of ozone by means of ultrasonic radiation. It was decided to investigate the effects of this ultrasonically produced ozone upon the ferrous ion. As far as the author has been able to determine, no work of this type has ever been published. This work, then, is of the nature of pioneering fundamental research.
A Colorimetric Quantitative Determination Of Aliphatic And Aromatic Nitro Compounds, George J. Kamin
A Colorimetric Quantitative Determination Of Aliphatic And Aromatic Nitro Compounds, George J. Kamin
Bachelors’ Theses
Becker and Shaefer mention that the qualitative test for nitro groups devised by Davidson could possibly be developed into a suitable quantitative test. It is the purpose of this work to attempt such an adaptation. This attempt is not one to develop a true speculative technique, but rather to derive a technique which could be of value in industrial usage, where time and money demand inexpensive rapid methods, which yield reasonable accuracy.
Relationship Of Bicarbonate Concentration Of Plant Tissue To That Of The Growth Media As A Factor In Chlorosis, Gary H. Carlsen
Relationship Of Bicarbonate Concentration Of Plant Tissue To That Of The Growth Media As A Factor In Chlorosis, Gary H. Carlsen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Throughout the years lime-induced chlorosis has contributed to untold economic losses. Although this disease has challenged the technical ingenuity of outstanding plant and soil scientists, the exact cause has never been determined; consequently, no preventative measures or permanent cures can, as yet, be recommended. This physiological malady, unchecked, continues its rampage in regions where the disease is prevalent.
The problem is of wide significance because calcareous soils are distributed throughout the world. It is of primary concern to us because the majority of the land of western United States is of this type. An estimated 500,000 acres of crops growing …
A Probe For Measuring Ultrasonic Pressures, Robert F. Rohrer
A Probe For Measuring Ultrasonic Pressures, Robert F. Rohrer
Masters Theses
"In the study of acoustics, the term ultrasonics is defined as those wave motions that have frequencies greater than about 20,000 cycles per second. The characteristics of a sound wave at any point in a medium can be regarded as completely defined when the amplitude, frequency, and phase of its Fourier components are known.
Sound measurements at their best are difficult. In the last few years sensitive linear microphones and electronic amplifiers have become available. Still, there are two difficulties of prime importance with their use in a sound field. First, there is the precise, absolute calibration of the equipment …
A Study Of Methods Of Preparation Of Phthalaldehyde, Harold Leon Chambers
A Study Of Methods Of Preparation Of Phthalaldehyde, Harold Leon Chambers
University of the Pacific Theses and Dissertations
Considerable work has been done in recent years on the general field centering around the chalcones, flavones, and anthocyanidins. Members of the three classes of compounds exist as natural products and occur widely as coloring matter in flowers and plant saps.
An attempt has been made to work out a new method for the preparation of phthalaldehyde. Two lines of research have been followed, neither of which produced the desired compound.
The first method, low-pressure hydrogenation of dibutylphthalate over Raney nickel catalyst has supported the contention that the principal product of the hydrogenation of aromatic esters over Raney nickel arises …
Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson
Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson
Theses and Dissertations
This work represents a study on the biological oxidation of molybdenite, MoS2. The principal objective of this study was to investigate the possibility of the biological oxidation of molybdenite, to determine the physical and chemical conditions under which the oxidative process occurs, and to develop a strain of bacteria or alter the activity of the microorganisms by acclimatization to increase their activity on sulfide minerals, in particular molybdenite. Minerals used in this study were pyrite (FeS2), chalcopyrite (CuFeS2), molybdenite concentrate, and molybdenite ore. The microorganisms used in this investigation were autotrophic bacteria obtained from the leaching streams of Bingham Canyon, …
Tetrazolium Salts, Andrew Garnett Richardson
Tetrazolium Salts, Andrew Garnett Richardson
Master's Theses
Tetrazolium salts, as the name indicates, are quartenary. Substitution is possible on positions 2, 3, and 5 of the ring as is shown in type formula (I). When these substituent groups are bifunctional ditetrazolium salts of types (II), (III), and (IV) result. Compounds bridged at both R' and R'' at the same time are theoretical possible, but no such cases have been reported, probably on account of the practical limitations of synthesis. The anion, which is indicated by X, may be halide, sulfate, acetate, picrate, succinate, thiocyanate, or practically any atom or group capable of existing as a negative ion.
Stapes Ankylosis And Its Mobilization, Emery I. Pick
Stapes Ankylosis And Its Mobilization, Emery I. Pick
Loma Linda University Electronic Theses, Dissertations & Projects
[Abstract Not Included - Preface Included Here]
Otosclerosis is a frequent affliction resulting in progressive hearing loss. With the advance of ear surgery during the past 25 years various procedures have been proposed for the correction of this condition. Among their number surgical mobilization of the stapes has assumed considerable importance. In this paper, which is presented as a thesis to fulfill the requirements for the degree of Master of Science, the operation will be discussed on the basis of the literature and the author's own experiences with the procedure.
Rapid Method For The Paper Chromatographic Separation Of Amino Acids In Urine, John J. Magruder
Rapid Method For The Paper Chromatographic Separation Of Amino Acids In Urine, John J. Magruder
Bachelors’ Theses
In the study of rapid analytical procedures, the author became interested in the field of chromatography. The difficulty of making rapid determinations of minute quantities of the amino acids led to this investigation of paper chromatography. The source of amino acids used in this work are the free amino acids contained in human urine. The rapidity of determining the amino acids was the critical interest in this work. Two-dimensional and circular chromatograms were both investigated to determine which method was the better suited to accomplish the rapid separation of the amino acids.
The Influence Of Soil Moisture Conditions On The Absorption Of Phosphorus By Plants From Calcareous Soils, T. J. Denman
The Influence Of Soil Moisture Conditions On The Absorption Of Phosphorus By Plants From Calcareous Soils, T. J. Denman
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Phosphorus is one of the major plant nutrients secured from the soil. The object of many investigations has been to discover the nature of the processes by which the soil supplies phosphorus to plants, and to determine the influence of soil factors upon these processes. Although much knowledge has been gained, these processes and the effects of soil factors upon them are still not clearly defined.
One factor which profoundly affects plant growth is the amount and relative availability of soil moisture. The results of some investigations have suggested that this factor may also have considerable influence on the absorption …